Question: What do the following two equations represent? $-x+y = 5$ $3x-3y = -15$
Answer: Putting the first equation in $y = mx + b$ form gives: $-x+y = 5$ $y = x+5$ Putting the second equation in $y = mx + b$ form gives: $3x-3y = -15$ $-3y = -3x-15$ $y = 1x + 5$ The above equations turn into the same equation, so they represent equal lines.